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Updated: May 28, 2026

Isolation and Selection of Entomopathogenic Fungi from Soil Samples and Evaluation of Fungal Virulence against Insect Pests
Published on: September 28, 2021
[Fungal nail infections - an update. Part 2 - From the causative agent to diagnosis - conventional and molecular
P Nenoff1, G Ginter-Hanselmayer, H-J Tietz
1Haut- und Laborarzt/Allergologie, Andrologie, Labor für medizinische Mikrobiologie, Straße des Friedens 8, 04579, Mölbis, Deutschland. nenoff@mykologie-experten.de
Abstract:
Trichophyton (T.) rubrum is the most frequently isolated dermatophyte in onychomycosis, both in Germany and worldwide. T. interdigitale (formerly T. mentagrophytes var. interdigitale) follows in second place. A further however rarely isolated dermatophyte in onychomycosis is Epidermophyton floccosum. Candida parapsilosis, Candida guilliermondii, and Candida albicans, followed by Trichosporon spp. are the most important yeasts which are found in onychomycosis. The molds most often responsible include Scopulariopsis brevicaulis, and several Aspergillus species, e. g. Aspergillus versicolor, and Fusarium spp. These so called non-dermatophyte molds (NDM) are increasingly isolated as emerging pathogens in onychomycosis. The diagnosis of onychomycosis should be verified in the mycology laboratory. Conventional diagnostic methods include the direct examination, ideally using fluorescence staining with Calcofluor® or Blancophor®, and culture. However, new molecular biological methods primarily employing the polymerase chain reaction (PCR) for direct detection of dermatophyte DNA in skin scrapings and nail samples have been introduced into routine mycological diagnostics. The diagnostic sensitivity is higher when both conventional and molecular procedures are combined.
Insights
Trichophyton rubrum is the most common cause of fungal nail infections (onychomycosis) globally. Combining traditional methods with new molecular techniques like PCR improves diagnostic accuracy for nail infections.
Area of Science:
- Medical Mycology
- Infectious Diseases
Context:
- Onychomycosis is a common fungal infection affecting toenails and fingernails.
- Accurate identification of causative agents is crucial for effective treatment.
Purpose:
- To review the common fungal pathogens causing onychomycosis.
- To discuss conventional and molecular diagnostic methods for onychomycosis.
Summary:
- Trichophyton rubrum and T. interdigitale are the leading dermatophytes causing onychomycosis.
- Yeasts like Candida spp. and non-dermatophyte molds (NDM) such as Scopulariopsis and Aspergillus are also implicated.
- Conventional diagnostics (direct microscopy, culture) and molecular methods (PCR) are used, with combined approaches offering higher sensitivity.
Impact:
- Highlights the spectrum of fungal organisms responsible for onychomycosis.
- Emphasizes the importance of laboratory diagnosis for identifying specific pathogens.
- Advocates for the integration of molecular techniques to enhance diagnostic performance in mycology.
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